Speaker
Description
Rodrigo Rosa-Medina, Francesco Ferri, Fabian Finger, Nicola Reiter, Tobias Donner, Tilman Esslinger
Institute for Quantum Electronics, ETH Zurich
Ultracold atoms coupled to high-finesse optical resonators are a versatile platform to simulate solid-state quantum systems and to explore out-of-equilibrium scenarios beyond conventional materials [1]. This is due to the high degree of experimental control and access. In particular, long-range interactions between the atoms are engineered by scattering of photons from tailored laser drives, while cavity leakage facilitates real-time access to the dynamics of these open quantum system.
In this talk, I will introduce the main concepts of this experimental platform [2]. As an illustrative example, I report on the experimental realization of dynamical tunneling in a synthetic lattice geometry [3]. Our implementation relies on a spinor Bose-Einstein condensate (BEC) coupled to the cavity and driven by two transverse laser fields. This induces superradiant Raman scattering with the photons imparting recoil momenta on the BEC, which we interpret as cavity-assisted hopping in a momentum space lattice. As the cavity field depends on the local density configuration, the tunneling rate evolves dynamically with the atomic state. By leveraging on the cavity leakage, we measure the emerging currents in real-time and non-destructively.
Very recently, we extended our experiments to a far off-resonant regime in order mitigate non-Hermitian processes. There, we observe the formation of correlated spin-pairs via 4-photon Raman processes, which are ejected out of the BEC at opposite momenta. Our results provide prospects to implement dynamical gauge fields and time reversal protocols to detect scrambling dynamics far from equilibrium.
[1] Mivehvar F., Piazza F., Donner T. , Ritsch H. (2021). Advances in Physics, 70:1, 1-153
[2] Ferri, F., Rosa-Medina, R., Finger, F., Dogra, N., Soriente, M., Zilberberg, O., Donner, T., Esslinger, T. (2021). PRX 11, 041046
[3] Rosa-Medina, R., Ferri, F., Finger, F., Dogra, N., Kroeger, K., Lin, R., Chitra, R., Donner, T., Esslinger, T. (2021). arXiv:2108.11888
